refactor(notification_bot): use ParseMode enum for bot default

modules/notification_bot.py

@@ -1,8 +1,9 @@
 import logging
 
 from aiogram import Bot
-from aiogram.types import InlineKeyboardButton, InlineKeyboardMarkup
+from aiogram.enums import ParseMode
 from aiogram.client.default import DefaultBotProperties
+from aiogram.types import InlineKeyboardButton, InlineKeyboardMarkup
 
 from config import Config
 from typing import Dict, Any, List
@@ -18,7 +19,7 @@ class NotificationBot:
             self.bot: Bot = Bot(
                 token=config.bot_token,
                 default=DefaultBotProperties(
-                    parse_mode="HTML",
+                    parse_mode=ParseMode.HTML,
                     disable_notification=True,
                     link_preview_is_disabled=True,
                 ),